Dual-targeting immunotherapy shows 99.2% remission in relapsed childhood leukemia

Chimeric antigen receptor (CAR) T–cell therapy, which reprograms a patient’s own immune cells to recognize and attack cancer, has transformed treatment for children with relapsed or refractory B-cell acute lymphoblastic leukemia (B-ALL). However, some patients still experience relapse, most often because leukemia cells stop expressing CD19, the protein targeted by conventional CAR T–cell therapies.

To overcome this challenge, researchers engineered CAR T cells to target both CD19 and a second protein, CD22. This dual-targeting approach has already shown promise in preclinical studies and early-phase clinical trials.

Building on those findings, an international Phase 2 clinical trial co-led by Ching-Hon Pui, MD, Department of Oncology, demonstrated that CAR T cells targeting both CD19 and CD22 achieved a 99.2% complete remission rate. The study enrolled 308 pediatric patients at hospitals across China, making it the largest trial to evaluate the dual-targeting strategy so far. Published in JAMA Oncology, the results provide the strongest evidence to date supporting the dual-targeting therapy’s effectiveness in children with relapsed or refractory B-ALL.

“Bicistronic CD19/CD22 CAR T–cell therapy was associated with high rates of deep remission and durable disease control in pediatric relapsed or refractory B-ALL,” Pui said.

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